Chrysenes for deep blue luminescent applications

ABSTRACT

This disclosure relates to chrysene compounds with deep blue emission that are useful in electroluminescent applications. It also relates to electronic devices in which the active layer includes such a chrysene compound.

RELATED APPLICATION DATA

This application claims priority under 35 U.S.C. § 119(e) from U.S.Provisional Application No. 60/941,383 filed on Jun. 1, 2007, which isincorporated by reference herein in its entirety.

BACKGROUND

1. Field of the Disclosure This disclosure relates to electroluminescentchrysene compounds that have deep blue emission. It also relates toelectronic devices in which the active layer includes such a chrysenecompound.

2. Description of the Related Art

Organic electronic devices that emit light, such as light-emittingdiodes that make up displays, are present in many different kinds ofelectronic equipment. In all such devices, an organic active layer issandwiched between two electrical contact layers. At least one of theelectrical contact layers is light-transmitting so that light can passthrough the electrical contact layer. The organic active layer emitslight through the light-transmitting electrical contact layer uponapplication of electricity across the electrical contact layers.

It is well known to use organic electroluminescent compounds as theactive component in light-emitting diodes. Simple organic molecules suchas anthracene, thiadiazole derivatives, and coumarin derivatives areknown to show electroluminescence. Semiconductive conjugated polymershave also been used as electroluminescent components, as has beendisclosed in, for example, U.S. Pat. No. 5,247,190, U.S. Pat. No.5,408,109, and Published European Patent Application 443 861.

However, there is a continuing need for electroluminescent compounds,especially compounds that are blue-emitting.

SUMMARY

There is provided a compound having Formula I:

wherein:

-   -   Ar1 and Ar3 are the same or different and are aryl, and at least        one of Ar1 and Ar3 has at least one electron-withdrawing        substituent;    -   Ar2 and Ar4 are the same or different and are aryl;    -   R1, R2, and R4 are the same or different and are selected from        the group consisting of H and an electron-withdrawing group;    -   R3 is an electron-withdrawing group;    -   R5 and R7 through R11 are the same or different and are selected        from the group consisting of H and alkyl;        wherein said compound is capable of emitting deep blue light.

There is also provided an electronic device comprising an active layercomprising the compound of Formula I.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments are illustrated in the accompanying figures to improveunderstanding of concepts as presented herein.

FIG. 1 includes an illustration of one example of an organic electronicdevice.

Skilled artisans appreciate that objects in the figures are illustratedfor simplicity and clarity and have not necessarily been drawn to scale.For example, the dimensions of some of the objects in the figures may beexaggerated relative to other objects to help to improve understandingof embodiments.

DEFINITION OF TERMS

As used herein, the term “compound” is intended to mean an electricallyuncharged substance made up of molecules that further consist of atoms,wherein the atoms cannot be separated by physical means. The phrase“adjacent to,” when used to refer to layers in a device, does notnecessarily mean that one layer is immediately next to another layer. Onthe other hand, the phrase “adjacent R groups,” is used to refer to Rgroups that are next to each other in a chemical formula (I.e., R groupsthat are on atoms joined by a bond). The term “photoactive” refers toany material that exhibits electroluminescence and/or photosensitivity.

The term “electron-withdrawing” as it refers to a substituent group isintended to mean a group which decreases the electron density of anaromatic ring.

The term “aryl” is intended to mean a group derived from an aromatichydrocarbon having one point of attachment. The term includes groupswhich have a single ring and those which have multiple rings which canbe joined by a single bond or fused together. The term is intended toinclude heteroaryls. The term “arylene” is intended to mean a groupderived from an aromatic hydrocarbon having two points of attachment. Insome embodiments, an aryl group has from 3-60 carbon atoms.

The term “alkyl” is intended to mean a group derived from an aliphatichydrocarbon having one point of attachment, and includes a linear, abranched, or a cyclic group. The term is intended to includeheteroalkyls. The term “alkylene” is intended to mean a group derivedfrom an aliphatic hydrocarbon and having two or more points ofattachment. In some embodiments, an alkyl group has from 1-20 carbonatoms.

The term “binaphthyl” is intended to mean a group having two naphthaleneunits joined by a single bond. In some embodiments, the binaphthyl groupis 1,1-binaphthyl, which is attached at the 3-, 4-, or 5-position; insome embodiments, 1,2-binaphthyl, which is attached at the 3-, 4-, or5-position on the 1-naphthyl moiety, or the 4- or 5-position on the2-naphthyl moiety; and in some embodiments, 2,2-binaphthyl, which isattached at the 4- or 5-position.

The term “biphenyl” is intended to mean a group having two phenyl unitsjoined by a single bond. The group can be attached at the 2-, 3-, or4-position.

The term “deep blue” refers to radiation that has an emission maximum ofphotoluminescence at a wavelength in a range of approximately 400-475nm. In some embodiments, deep blue light has color coordinates ofx=0.1-0.2, and y<0.1, according to the C.I.E. chromaticity scale(Commision Internationale de L'Eclairage, 1931).

The prefix “fluoro” indicates that one or more available hydrogen atomsin a compound have been replaced with F. The prefix “perfluoro”indicates that all available hydrogen atoms have been replace with F.

The prefix “hetero” indicates that one or more carbon atoms have beenreplaced with a different atom. In some embodiments, the different atomis N, O, or S.

All groups may be unsubstituted or substituted. In some embodiments, thesubstituents are selected from the group consisting of halide, alkyl,alkoxy, aryl, and cyano.

The term “layer” is used interchangeably with the term “film” and refersto a coating covering a desired area. The term is not limited by size.The area can be as large as an entire device or as small as a specificfunctional area such as the actual visual display, or as small as asingle sub-pixel. Layers and films can be formed by any conventionaldeposition technique, including vapor deposition, liquid deposition(continuous and discontinuous techniques), and thermal transfer.Continuous deposition techniques, include but are not limited to, spincoating, gravure coating, curtain coating, dip coating, slot-diecoating, spray coating, and continuous nozzle coating. Discontinuousdeposition techniques include, but are not limited to, ink jet printing,gravure printing, and screen printing.

The term “organic electronic device,” or sometimes just “electronicdevice,” is intended to mean a device including one or more organicsemiconductor layers or materials.

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. Although methods and materialssimilar or equivalent to those described herein can be used in thepractice or testing of the present invention, suitable methods andmaterials are described below. All publications, patent applications,patents, and other references mentioned herein are incorporated byreference in their entirety. In case of conflict, the presentspecification, including definitions, will control. In addition, thematerials, methods, and examples are illustrative only and not intendedto be limiting.

The IUPAC numbering system is used throughout, where the groups from thePeriodic Table are numbered from left to right as 1-18 (CRC Handbook ofChemistry and Physics, 81^(st) Edition, 2000).

DETAILED DESCRIPTION

One aspect of the present invention is a composition of Formula I:

wherein:

-   -   Ar1 and Ar3 are the same or different and are aryl, and at least        one of Ar1 and Ar3 has at least one electron-withdrawing        substituent;    -   Ar2 and Ar4 are the same or different and are aryl;    -   R1, R2, and R4 are the same or different and are selected from        the group consisting of H and an electron-withdrawing group;    -   R3 is an electron-withdrawing group;    -   R5 and R7 through R11 are the same or different and are selected        from the group consisting of H and alkyl.        The compound is capable of deep blue emission.

In some embodiments, the electron-withdrawing group (“EWG”) is selectedfrom the group consisting of fluoro, cyano, perfluoroalkyl,perfluoroaryl, nitro, —SO₂R, where R is alkyl or perfluoroalkyl, andcombinations thereof. In some embodiments, the EWG is fluoro.

In some embodiments, both R1 and R3 are EWGs. In some embodiments, R3,R5, and R7 through R11 are H.

In some embodiments, Ar1 through Ar4 are independently selected from thegroup consisting of phenyl, biphenyl, naphthyl, and binaphthyl.

In some embodiments, both Ar1 and Ar3 have at least one EWG. In someembodiments, they have two or more EWGs. In some embodiments, both Ar1and Ar3 are phenyl groups.

In some embodiments, at least one of Ar2 and Ar4 has at least one alkylsubstituent. In some embodiments, the alkyl group has 1-8 carbon atoms.In some embodiments, at least one of Ar2 and Ar4 has at least one EWG.In some embodiments, both Ar2 and Ar4 are biphenyl.

In some embodiments, each of Ar1, Ar2, Ar3, and Ar4 has at least oneEWG.

In some embodiments, Ar1 and Ar3 are phenyl groups having at least oneEWG and Ar2 and Ar4 are biphenyl groups having at least one substituentselected from the group consisting of alkyl and EWG.

In some embodiments, the deep blue chrysene compound is selected fromCompound E-1 and Compound E-2:

The new chrysenes can be prepared by known coupling and substitutionreactions. An exemplary preparation is given in the Examples.

The chrysene compounds described herein can be formed into films usingliquid deposition techniques. Thin films of these materials dispersed ina host matrix exhibit good to excellent photoluminescent properties anddeep blue emission.

3. Electronic Device

Organic electronic devices that may benefit from having one or morelayers comprising the deep blue luminescent materials described hereininclude, but are not limited to, (1) devices that convert electricalenergy into radiation (e.g., a light-emitting diode, light emittingdiode display, or diode laser), (2) devices that detect signals throughelectronics processes (e.g., photodetectors, photoconductive cells,photoresistors, photoswitches, phototransistors, phototubes, IRdetectors), (3) devices that convert radiation into electrical energy,(e.g., a photovoltaic device or solar cell), and (4) devices thatinclude one or more electronic components that include one or moreorganic semi-conductor layers (e.g., a transistor or diode). Thesedevices generally comprise first and second electrical contact layerswith at least one organic active layer between the two contact layers.

One illustration of an organic electronic device structure is shown inFIG. 1. The device 100 has a first electrical contact layer, an anodelayer 110 and a second electrical contact layer, a cathode layer 160,and a photoactive layer 140 between them. Adjacent to the anode is abuffer layer 120. Adjacent to the buffer layer is a hole transport layer130, comprising hole transport material. Adjacent to the cathode may bean electron transport layer 150, comprising an electron transportmaterial. As an option, devices may use one or more additional holeinjection or hole transport layers (not shown) next to the anode 110and/or one or more additional electron injection or electron transportlayers (not shown) next to the cathode 160.

Layers 120 through 150 are individually and collectively referred to asthe active layers.

In one embodiment, the different layers have the following range ofthicknesses: anode 110, 500-5000 Å, in one embodiment 1000-2000 Å;buffer layer 120, 50-2000 Å, in one embodiment 200-1000 Å; holetransport layer 130, 50-2000 Å, in one embodiment 200-1000 Å;photoactive layer 140, 10-2000 Å, in one embodiment 100-1000 Å; layer150, 50-2000 Å, in one embodiment 100-1000 Å; cathode 160, 200-10000 Å,in one embodiment 300-5000 Å. The location of the electron-holerecombination zone in the device, and thus the emission spectrum of thedevice, can be affected by the relative thickness of each layer. Thedesired ratio of layer thicknesses will depend on the exact nature ofthe materials used.

Depending upon the application of the device 100, the photoactive layer140 can be a light-emitting layer that is activated by an appliedvoltage (such as in a light-emitting diode or light-emittingelectrochemical cell), or a layer of material that responds to radiantenergy and generates a signal with or without an applied bias voltage(such as in a photodetector). Examples of photodetectors includephotoconductive cells, photoresistors, photoswitches, phototransistors,and phototubes, and photovoltaic cells, as these terms are described inMarkus, John, Electronics and Nucleonics Dictionary, 470 and 476(McGraw-Hill, Inc. 1966).

a. Photoactive Layer

The chrysene compounds of Formula I are useful as photoactive materialsin layer 140. The compounds can be used alone, or in combination with ahost material.

In some embodiments, the host is a bis-condensed cyclic aromaticcompound.

In some embodiments, the host is an anthracene derivative compound. Insome embodiments the compound has the formula:

An-L-An

where:

-   -   An is an anthracene moiety;    -   L is a divalent connecting group.        In some embodiments of this formula, L is a single bond, —O—,        —S—, —N(R)—, or an aromatic group. In some embodiments, An is a        mono- or diphenylanthryl moiety.

In some embodiments, the host has the formula:

A-An-A

where:

-   -   An is an anthracene moiety;    -   A is the same or different at each occurrence and is an aromatic        group.

In some embodiments, the A groups are attached at the 9- and10-positions of the anthracene moiety. In some embodiments, A isselected from the group consisting naphthyl, naphthylphenylene, andnaphthylnaphthylene. In some embodiments the compound is symmetrical andin some embodiments the compound is non-symmetrical.

In some embodiments, the host has the formula:

where:

A¹ and A² are the same or different at each occurrence and are selectedfrom the group consisting of H, an aromatic group, and an alkenyl group,or A may represent one or more fused aromatic rings;

p and q are the same or different and are an integer from 1-3. In someembodiments, the anthracene derivative is non-symmetrical. In someembodiments, p=2 and q=1. In some embodiments, at least one of A¹ and A²is a naphthyl group.

In some embodiments, the host is selected from the group consisting of

and combinations thereof.

The chrysene compounds of Formula I, in addition to being useful asemissive dopants in the photoactive layer, can also act as chargecarrying hosts for other emissive dopants in the photoactive layer 140.

b. Other Device Layers

The other layers in the device can be made of any materials that areknown to be useful in such layers.

The anode 110, is an electrode that is particularly efficient forinjecting positive charge carriers. It can be made of, for example,materials containing a metal, mixed metal, alloy, metal oxide ormixed-metal oxide, or it can be a conducting polymer, or mixturesthereof. Suitable metals include the Group 11 metals, the metals inGroups 4-6, and the Group 8-10 transition metals. If the anode is to belight-transmitting, mixed-metal oxides of Groups 12, 13 and 14 metals,such as indium-tin-oxide, are generally used. The anode 110 can alsocomprise an organic material such as polyaniline as described in“Flexible light-emitting diodes made from soluble conducting polymer,”Nature vol. 357, pp 477-479 (11 Jun. 1992). At least one of the anodeand cathode is desirably at least partially transparent to allow thegenerated light to be observed.

The buffer layer 120 comprises buffer material and may have one or morefunctions in an organic electronic device, including but not limited to,planarization of the underlying layer, charge transport and/or chargeinjection properties, scavenging of impurities such as oxygen or metalions, and other aspects to facilitate or to improve the performance ofthe organic electronic device. Buffer materials may be polymers,oligomers, or small molecules. They may be vapour deposited or depositedfrom liquids which may be in the form of solutions, dispersions,suspensions, emulsions, colloidal mixtures, or other compositions.

The buffer layer can be formed with polymeric materials, such aspolyaniline (PANI) or polyethylenedioxythiophene (PEDOT), which areoften doped with protonic acids. The protonic acids can be, for example,poly(styrenesulfonic acid), poly(2-acrylamido-2-methyl-1-propanesulfonicacid), and the like.

The buffer layer can comprise charge transfer compounds, and the like,such as copper phthalocyanine and thetetrathiafulvalene-tetracyanoquinodimethane system (TTF-TCNQ).

In some embodiments, the buffer layer comprises at least oneelectrically conductive polymer and at least one fluorinated acidpolymer. Such materials have been described in, for example, publishedU.S. patent applications 2004-0102577, 2004-0127637, and 2005/205860

Examples of hole transport materials for layer 130 have been summarizedfor example, in Kirk-Othmer Encyclopedia of Chemical Technology, FourthEdition, Vol. 18, p. 837-860, 1996, by Y. Wang. Both hole transportingmolecules and polymers can be used. Commonly used hole transportingmolecules are:N,N′-diphenyl-N,N′-bis(3-methylphenyl)-[1,1′-biphenyl]-4,4′-diamine(TPD), 1,1-bis[(di-4-tolylamino) phenyl]cyclohexane (TAPC),N,N′-bis(4-methylphenyl)-N,N′-bis(4-ethylphenyl)-[1,1′-(3,3′-dimethyl)biphenyl]-4,4′-diamine(ETPD), tetrakis-(3-methylphenyl)-N,N,N′,N′-2,5-phenylenediamine (PDA),a-phenyl-4-N,N-diphenylaminostyrene (TPS), p-(diethylamino)benzaldehydediphenylhydrazone (DEH), triphenylamine (TPA),bis[4-(N,N-diethylamino)-2-methylphenyl](4-methylphenyl)methane (MPMP),1-phenyl-3-[p-(diethylamino)styryl]-5-[p-(diethylamino)phenyl]pyrazoline(PPR or DEASP), 1,2-trans-bis(9H-carbazol-9-yl)cyclobutane (DCZB),N,N,N′,N′-tetrakis(4-methylphenyl)-(1,1′-biphenyl)-4,4′-diamine (TTB),N,N′-bis(naphthalen-1-yl)-N,N′-bis-(phenyl)benzidine (α-NPB), andporphyrinic compounds, such as copper phthalocyanine. Commonly used holetransporting polymers are polyvinylcarbazole, (phenylmethyl)-polysilane,and polyaniline. It is also possible to obtain hole transportingpolymers by doping hole transporting molecules such as those mentionedabove into polymers such as polystyrene and polycarbonate. In somecases, triarylamine polymers are used, especially triarylamine-fluorenecopolymers. In some cases, the polymers and copolymers arecrosslinkable.

Examples of additional electron transport materials which can be used inlayer 150 include metal chelated oxinoid compounds, such astris(8-hydroxyquinolato)aluminum (Alq₃);bis(2-methyl-8-quinolinolato)(para-phenyl-phenolato)aluminum(III)(BAIQ); and azole compounds such as2-(4-biphenylyl)-5-(4-t-butylphenyl)-1,3,4-oxadiazole (PBD) and3-(4-biphenylyl)-4-phenyl-5-(4-t-butylphenyl)-1,2,4-triazole (TAZ), and1,3,5-tri(phenyl-2-benzimidazole)benzene (TPBI); quinoxaline derivativessuch as 2,3-bis(4-fluorophenyl)quinoxaline; phenanthroline derivativessuch as 9,10-diphenylphenanthroline (DPA) and2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (DDPA); and mixturesthereof. Layer 150 can function both to facilitate electron transport,and also serve as a buffer layer or confinement layer to preventquenching of the exciton at layer interfaces. Preferably, this layerpromotes electron mobility and reduces exciton quenching.

The cathode 160, is an electrode that is particularly efficient forinjecting electrons or negative charge carriers. The cathode can be anymetal or nonmetal having a lower work function than the anode. Materialsfor the cathode can be selected from alkali metals of Group 1 (e.g., Li,Cs), the Group 2 (alkaline earth) metals, the Group 12 metals, includingthe rare earth elements and lanthanides, and the actinides. Materialssuch as aluminum, indium, calcium, barium, samarium and magnesium, aswell as combinations, can be used. Li-containing organometalliccompounds, LiF, and Li₂O can also be deposited between the organic layerand the cathode layer to lower the operating voltage.

It is known to have other layers in organic electronic devices. Forexample, there can be a layer (not shown) between the anode 110 andbuffer layer 120 to control the amount of positive charge injectedand/or to provide band-gap matching of the layers, or to function as aprotective layer. Layers that are known in the art can be used, such ascopper phthalocyanine, silicon oxy-nitride, fluorocarbons, silanes, oran ultra-thin layer of a metal, such as Pt. Alternatively, some or allof anode layer 110, active layers 120, 130, 140, and 150, or cathodelayer 160, can be surface-treated to increase charge carrier transportefficiency. The choice of materials for each of the component layers ispreferably determined by balancing the positive and negative charges inthe emitter layer to provide a device with high electroluminescenceefficiency.

It is understood that each functional layer can be made up of more thanone layer.

The device can be prepared by a variety of techniques, includingsequential vapor deposition of the individual layers on a suitablesubstrate. Substrates such as glass, plastics, and metals can be used.Conventional vapor deposition techniques can be used, such as thermalevaporation, chemical vapor deposition, and the like. Alternatively, theorganic layers can be applied from solutions or dispersions in suitablesolvents, using conventional coating or printing techniques, includingbut not limited to spin-coating, dip-coating, roll-to-roll techniques,ink-jet printing, screen-printing, gravure printing and the like. Thelocation of the electron-hole recombination zone in the device, and thusthe emission spectrum of the device, can be affected by the relativethickness of each layer. Thus the thickness of the electron-transportlayer is desirably chosen so that the electron-hole recombination zoneis in the light-emitting layer. The desired ratio of layer thicknesseswill depend on the exact nature of the materials used.

The present invention also relates to an electronic device comprising atleast one active layer positioned between two electrical contact layers,wherein the at least one active layer of the device includes thechrysene compound of Formula I. Devices frequently have additional holetransport and electron transport layers.

It is understood that the efficiency of devices made with the chrysenecompounds described herein, can be further improved by optimizing theother layers in the device. For example, more efficient cathodes such asCa, Ba or LiF can be used. Shaped substrates and novel hole transportmaterials that result in a reduction in operating voltage or increasequantum efficiency are also applicable. Additional layers can also beadded to tailor the energy levels of the various layers and facilitateelectroluminescence.

The chrysene compounds of the invention often are fluorescent andphotoluminescent and can be useful in applications other than OLEDs,such as oxygen sensitive indicators and as fluorescent indicators inbioassays.

EXAMPLES

The following examples illustrate certain features and advantages of thepresent invention. They are intended to be illustrative of theinvention, but not limiting. All percentages are by weight, unlessotherwise indicated.

Example 1

This example illustrates the preparation of CompoundE-1,3-fluoro-N⁶,N¹²-bis(3-fluorophenyl)-N⁶,N¹²-bis(4-iso-propylphenyl)chrysene-6,12-diamine.

a. Preparation of 1-(4-fluorostyryl)naphthalene

An oven-dried 500 ml three-neck flask was purged with nitrogen andcharged with (naphthalen-1-ylmethyl)triphenylphosphonium (11.67 g, 26.6mmol) and dry THF (200 ml). Sodium hydride (1.06 g, 26.6 mmol) was addedand reaction mixture was left to stir overnight at room temperature.Solution was orange in the morning. A solution of 4-fluorobenzaldehyde(3.0 g, 24.2 mmol) in dry THF (30 ml) was added next day (16 h later)over the period of 45 minutes, bleaching the orange-red color. Reactionmixture was stirred at room temperature for 24 hours. THF was removedunder reduced pressure. Crude product was purified by columnchromoatography on silica gel with 5% CHCl₃ in hexanes. The desiredproduct is a mixture of cis- and trans-isomers. Yield 5.7 g (95%) of aviscous oil. The structure was confirmed by ¹H NMR spectroscopy.

b. Preparation of 3-fluorochrysene

A mixture of isomeric 4-(2-(naphthalen-1-yl)vinyl)benzonitriles (4 g,16.1 mmol) was dissolved in 40 ml of dry toluene and transferred into a1 L photochemical vessel, equipped with a nitrogen inlet and a stirbar.Next, dry toluene (1 L) was added by cannula, followed by iodine (4.17g, 16.4 mmol) and propylene oxide (100 ml). Two condensers were attachedon top of the photochemical vessel. The halogen lamp (Hanovia, 450 W)was turned on. Reaction was stopped by turning off the lamp when no moreiodine was left in the reaction mixture, as evidenced by thedisappearance of its color. Toluene and excess propylene oxide wereremoved under reduced pressure to give a yellow solid. The solid waswashed with hexane, affording white needles (2.79 g, 70%). The structureof this material was confirmed by ¹H NMR spectroscopy.

c. Preparation of 3-fluoro-6,12-dibromochrysene

3-Fluorochrysene (1 g, 3.94 mmol) was placed into a 100 ml round-bottomflask and suspended in 30 ml of (MeO)₃PO. Bromine (1.59 g, 10 mmol) wasadded next. Condenser was attached to the flask, which was brought to110° C. and stirred for 1 hour. Reaction mixture was then cooled to roomtemperature and poured into 250 ml of water. The resulting precipitatewas filtered again and washed with 100 ml of diethyl ether, giving 4.16g (91%) of the desired product. The identity of the product wasconfirmed by ¹H NMR spectroscopy.

d. Preparation of E1

In a drybox, 6,12-dibromo-3-fluorochrysene (1.0 g, 2.47 mmol) and3-fluoro-N-(4-iso-propylphenyl)aniline (1.19 g, 5.2 mmol) were combinedin a thick-walled glass tube and dissolved in 10 ml of toluene.Tris(tert-butyl)phosphine (0.09 g, 0.045 mmol) andtris(dibenzylideneacetone)dipalladium(0) (0.02 g, 0.022 mmol) pre-mixedin 10 ml of dry toluene were added next, followed by sodiumtert-butoxide (0.476 g, 4.94 mmol) and 10 ml of dry toluene. Glass tubewas sealed, brought out of the box and placed into a 80° C. oil bath for24 hours. Reaction mixture was cooled to room temperature and filteredthrough a plug of celite and silica. The plug was washed with additional500 ml of chloroform and 200 ml of dichloromethane. Filtrates werecombined and volatiles were removed under reduced pressure to give crudeproduct. Further purification was done by boiling the crude product in100 ml of hexane and filtering. The resulting white powder (1.25 g or73.%) was 97.3% pure by LC. The structure was confirmed by ¹H and ¹⁹FNMR spectroscopy. ¹H NMR (CD₂Cl₂): δ 1.15 (d, 12H, J=6.9 Hz), 2.79(sept, 2H, J=6.9 Hz), 6.51 (ddt, 2H, J=1 Hz, J=2.6 Hz, J=8.3 Hz), 6.61(dq, 2H, J=2.2 Hz, J=11.7 Hz), 6.68 (ddd, 2H, J=1 Hz, J=2.2 Hz, J=8.3Hz), 7.0-7.12 (m), 7.16-7.23 (m, 1H), 7.46 (dd, 1H, J=1 Hz, J=7.7 Hz),7.55 (dd, 1H, J=1.3 Hz, J=6.8 Hz), 8.0-8.06 (m, 2H), 8.12 (dd, 1H, J=2.4Hz, J=11.3 Hz), 8.35 (s, 1H), 8.46 (s, 1H), 8.51 (s, 1H, J=8.6 Hz). ¹⁹FNMR (CD₂Cl₂): δ −113.72 (m), −113.65 (m), −113.57 (m). PL (toluene, 15μM): 454 nm. CIE coordinates: x=0.139, y=0.09 (according to the C.I.E.chromaticity scale (Commision Internationale de L'Eclairage, 1931).

Example 2

This example illustrates the preparation of CompoundE-2,3-Fluoro-6,12-N,N′-(4-biphenyl)-6,12-N,N′-(3-fluorophenyl)chrysenediamine.

In a drybox, 6,12-dibromo-3-fluorochrysene (0.7 g, 1.73 mmol) and3-fluoro-N-(4-biphenylphenyl)aniline (0.96 g, 3. mmol) were combined ina thick-walled glass tube and dissolved in 10 ml of toluene.Tris(tert-butyl)phosphine (0.0065 g, 0.032 mmol) andtris(dibenzylideneacetone)dipalladium(0) (0.015 g, 0.016 mmol),pre-mixed in 10 ml of dry toluene for ten minutes, were added next,followed by sodium tert-butoxide (0.33 g, 3.46 mmol) and 10 ml of drytoluene. Glass tube was sealed, brought out of the box and placed intoan 80° C. oil bath for 24 hours. Reaction mixture was cooled to roomtemperature and filtered through a plug of celite and silica. The plugwas washed with additional 500 ml of dichloromethane. Filtrates werecombined and volatiles were removed under reduced pressure to give crudeproduct. Further purification was done by boiling the crude product inmethanol and filtering. The resulting white powder (1.1 g or 84.6%) was99% pure by LC. The structure was confirmed by ¹H NMR spectroscopy. ¹HNMR (DMF-d₇): δ 6.96-7.04 (m, 2H), 7.1 (app tt, 2H, J=1.3, 12.1 Hz),7.16 (app dt, 2H, J=2.3, 10.3 Hz), 7.50-7.60 (m, 8H), 7.65 (app td, 4H,J=2.1, 7.8 Hz), 7.76 (app td, ¹H, J=2.5, 8.7 Hz), 7.86-7.98 (m, 10H),8.41 (dd, 1H, J=1.0, 8.2 Hz), 8.46 (dd, ¹H, J=6.0, 9.2 Hz), 9.09 (dd,¹H, J=2.5, 11.6 Hz), 9.2 (d, 1H, 8.2 Hz), 9.22 (s, 1H), 9.30 (s, 1H). PL(toluene, 15 uM): 451 nm. CIE coordinates: x 0.143, y 0.078.

Example 3

This example demonstrates the fabrication and performance of a devicehaving deep blue emission using Compound E-1 from Example 1. Thefollowing materials were used:

-   -   Indium Tin Oxide (ITO): 50 nm    -   buffer layer=Buffer 1 (15 nm), which is an aqueous dispersion of        polypyrrole and a polymeric fluorinated sulfonic acid. The        material was prepared using a procedure similar to that        described in Example 1 of published U.S. patent application no.        2005/0205860.    -   hole transport layer=polymer P1 (20 nm)    -   photoactive layer=13:1 host H1:dopant E-1 (48 nm)    -   electron transport layer=Tetrakis-(8-hydroxyquinoline) zirconium        (ZrQ) (20 nm)    -   cathode=LiF/Al (0.5/100 nm)

OLED devices were fabricated by a combination of solution processing andthermal evaporation techniques. Patterned indium tin oxide (ITO) coatedglass substrates from Thin Film Devices, Inc were used. These ITOsubstrates are based on Corning 1737 glass coated with ITO having asheet resistance of 50 ohms/square and 80% light transmission. Thepatterned ITO substrates were cleaned ultrasonically in aqueousdetergent solution and rinsed with distilled water. The patterned ITOwas subsequently cleaned ultrasonically in acetone, rinsed withisopropanol, and dried in a stream of nitrogen.

Immediately before device fabrication the cleaned, patterned ITOsubstrates were treated with UV ozone for 10 minutes. Immediately aftercooling, an aqueous dispersion of Buffer 1 was spin-coated over the ITOsurface and heated to remove solvent. After cooling, the substrates werethen spin-coated with a solution of a hole transport material, and thenheated to remove solvent. After cooling the substrates were spin-coatedwith the emissive layer solution, and heated to remove solvent. Thesubstrates were masked and placed in a vacuum chamber. A ZrQ layer wasdeposited by thermal evaporation, followed by a layer of LiF. Masks werethen changed in vacuo and a layer of Al was deposited by thermalevaporation. The chamber was vented, and the devices were encapsulatedusing a glass lid, dessicant, and UV curable epoxy.

The OLED samples were characterized by measuring their (1)current-voltage (I-V) curves, (2) electroluminescence radiance versusvoltage, and (3) electroluminescence spectra versus voltage. All threemeasurements were performed at the same time and controlled by acomputer. The current efficiency of the device at a certain voltage isdetermined by dividing the electroluminescence radiance of the LED bythe current density needed to run the device. The unit is a cd/A. Thepower efficiency is the current efficiency divided by the operatingvoltage. The unit is Im/W. The results are given in Table 1.

Example 4

A device was made and tested according to the procedure of Example 3,using E-2 as the dopant and H1 as the host. The results are given inTable 1.

Example 5

A device was made and tested according to the procedure of Example 3,using E-2 as the dopant and H2 as the host. The results are given inTable 1.

TABLE 1 CE Voltage EL peak Lum. ½ Example [cd/A] (V) [nm] CIE [x] CIE[y] Life [h] 3 1.3 4.3 454 0.15 0.10  550 4 1.6 6.9 454 0.14 0.11 1100 51.8 6.3 454 0.14 0.11 1650 *All data @ 2000 nits, CE = currentefficiency, LT projected for 1000 nit operation. P1

Note that not all of the activities described above in the generaldescription or the examples are required, that a portion of a specificactivity may not be required, and that one or more further activitiesmay be performed in addition to those described. Still further, theorder in which activities are listed are not necessarily the order inwhich they are performed.

In the foregoing specification, the concepts have been described withreference to specific embodiments. However, one of ordinary skill in theart appreciates that various modifications and changes can be madewithout departing from the scope of the invention as set forth in theclaims below. Accordingly, the specification and figures are to beregarded in an illustrative rather than a restrictive sense, and allsuch modifications are intended to be included within the scope ofinvention.

Benefits, other advantages, and solutions to problems have beendescribed above with regard to specific embodiments. However, thebenefits, advantages, solutions to problems, and any feature(s) that maycause any benefit, advantage, or solution to occur or become morepronounced are not to be construed as a critical, required, or essentialfeature of any or all the claims.

The use of numerical values in the various ranges specified herein isstated as approximations as though the minimum and maximum values withinthe stated ranges were both being preceded by the word “about.” In thismanner slight variations above and below the stated ranges can be usedto achieve substantially the same results as values within the ranges.Also, the disclosure of these ranges is intended as a continuous rangeincluding every value between the minimum and maximum average valuesincluding fractional values that can result when some of components ofone value are mixed with those of different value. Moreover, whenbroader and narrower ranges are disclosed, it is within thecontemplation of this invention to match a minimum value from one rangewith a maximum value from another range and vice versa.

It is to be appreciated that certain features are, for clarity,described herein in the context of separate embodiments, may also beprovided in combination in a single embodiment. Conversely, variousfeatures that are, for brevity, described in the context of a singleembodiment, may also be provided separately or in any subcombination.

1. A compound having Formula I:

wherein: Ar1 and Ar3 are the same or different and are aryl, and atleast one of Ar1 and Ar3 has at least one electron-withdrawingsubstituent; Ar2 and Ar4 are the same or different and are aryl; R1, R2,and R4 are the same or different and are selected from the groupconsisting of H and an electron-withdrawing group; R3 is anelectron-withdrawing group; R5 and R7 through R11 are the same ordifferent and are selected from the group consisting of H and alkyl;wherein said compound is capable of emitting deep blue light.
 2. Thecompound of claim 1, wherein the electron-withdrawing group is selectedfrom group consisting of fluoro, cyano, perfluoroalkyl, nitro,perfluoroaryl, —SO₂R, and combinations thereof, where R is alkyl orperfluoroalkyl.
 3. The compound of claim 1, wherein R1 is anelectron-withdrawing group and R2, R5, and R7 through R11 are H.
 4. Thecompound of claim 1, wherein both Ar1 and Ar3 have at least oneelectron-withdrawing substituent.
 5. The compound of claim 4, whereinboth Ar1 and Ar3 have two or more electron-withdrawing substituents. 6.The compound of claim 1, wherein Ar1 and Ar3 are phenyl.
 7. The compoundof claim 1, wherein Ar2 and Ar4 are selected from the group consistingof phenyl, biphenyl, naphthyl, and binaphthyl.
 8. The compound of claim7, wherein Ar2 and Ar4 are biphenyl.
 9. The compound of claim 7, whereinat least one of Ar2 and Ar4 has at least one alkyl substituent.
 10. Thecompound of claim 4, wherein Ar2 and Ar4 each have at least oneelectron-withdrawing substituent.
 11. An organic electronic devicecomprising a first electrical contact layer, a second electrical contactlayer, and at least one active layer therebetween, wherein the activelayer comprises a compound having Formula I:

wherein: Ar1 and Ar3 are the same or different and are aryl, and atleast one of Ar1 and Ar3 has at least one electron-withdrawingsubstituent; Ar2 and Ar4 are the same or different and are aryl; R1, R2,and R4 are the same or different and are selected from the groupconsisting of H and an electron-withdrawing group; R3 is anelectron-withdrawing group; R5 and R7 through R11 are the same ordifferent and are selected from the group consisting of H and alkyl;wherein said compound is capable of emitting deep blue light.
 12. Anactive layer comprising a compound as in any one of claims 1 through 10.13. The active layer of claim 12 further comprising a host material. 14.The active layer of claim 13 wherein the host material has the formula:A-An-A where: An is an anthracene moiety; A is the same or different ateach occurrence and is an aromatic group.
 15. The active layer of claim14 wherein the host has the formula:

where: A¹ and A² are the same or different at each occurrence and areselected from the group consisting of H, an aromatic group, and analkenyl group, or A may represent one or more fused aromatic rings; pand q are the same or different and are an integer from 1-3.
 16. Theactive layer of claim 15 wherein at least one of A¹ and A² comprises anaphthyl group.
 17. the active layer of claim 16 wherein the host isselected from the group consisting of

and combinations thereof.
 18. The active layer of claim 13 wherein thehost has the formula:An-L-An where: An is an anthracene moiety; L is a divalent connectinggroup.